Surface treating apparatus



Nov. 9, 1965 s. CARL-OSKAR ERNOLF SURFACE TREATING APPARATUS Filed July 11, 1963 6 Sheets-Sheet 1 (fi INVENTOR.

z BY WWI/kw A 7 Tom/5y 1965 s. CARL-OSKAR ERNOLF 3,216,047

SURFACE TREATING APPARATUS 6 Sheets-Sheet 2 Filed July 11, 1963 A Tram/5y 1965 s. CARL-OSKAR ERNOLF 3,216,047

SURFACE TREATING APPARATUS Filed July 11, 1963 6 Sheets-Sheet 3 INVENTOR.

BY Mi M Nov. 9, 1965 s. CARL-OSKAR ERNOLF 3, 7

SURFACE TREATING APPARATUS Filed July 11, 1963 6 Sheets-Sheet 4 INVENTOR.

Nov. 9, 1965 s. CARL-OSKAR ERNOLF 3,

SURFACE TREATING APPARATUS Filed July 11, 1963 6 Sheets-Sheet 5 FIG. 5 d

INVENTOR.

N 1965 s. CARL-OSKAR ERNOLF 3,215,047

SURFACE TREATING APPARATUS INVENTOR.

ATTOE/V' Unite 3,215,,tl47 Patented Nov. 9, 1965 3316347 SURFAE TREATENG APPARATUS Stig Carl-Oskar Ernolf, Stockholm, Sweden, assignor to Aktiebolaget Electrolux, Stockholm, Sweden, :1 corporation of Sweden Filed July 11, 1963, Ser. No. 294,359 14 (Ilaims. ((31. -635) This invention relates to surface treating apparatus having one or more rotatable brushes adapted to be positioned on a surface and moved thereover.

It has been proposed to mount brushes on driven rotatable members in such manner that the brushes are angularly movable on the rotatable members. It also has been the practice heretofore to detachably fasten the brushes on the driven rotatable members.

It is an object of this invention to provide improved surface treating apparatus of this kind having a member of annular form fixed to the driven rotatable member which forms a skirt and coacts with the brush back to limit angular movement of the brush on the driven rotatable member.

Another object is to provide improved mechanism for detachably fastening brushes on driven rotatable memhere.

A further object is to provide an improved surface treating apparatus in which the skirt functioning to limit angular movement of the brush forms part of structure defining an outlet of an air passageway through which air is discharged at the vicinity of the brush toward the surface being treated.

A still further object is to provide improved surface treating apparatus of this kind in which an opening in a brush back defines an outlet for discharging air at the vicinity of the brush from a passageway having an air gap formed at a region at which a lug extends upward from the brush back into a slot in a driven rotatable member to impart turning movement to the brush.

A still further object is to provide improved surface treating apparatus of this kind having a base including a side wall formed of elastomeric material which is of simplified construction and can be readily assembled.

A still further object is to provide improved surface treating apparatus of this kind in which the driven rotatable member upon which the brush is mounted and to which it is detachably fastened includes components respectively formed of metal and plastic.

A still further object is to provide improved surface treating apparatus in which the end thrust of the driven rotatable member and brush mounted thereon is taken up by a thrust bearing plate which receives lubricant from a source of supply closely adjacent thereto.

Further objects and advantages of the invention will become apparent as the following description proceeds, and the features of novelty which characterize the invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.

For a better understanding of the invention, reference may be had to the following description taken in connection with the accompanying drawing, in which:

FIG. 1 is a front view, partly broken away and in sec tion, of surface treating apparatus embodying the invention;

FIG. 2 is a horizontal sectional view taken at line 2-2 of FIG. 1;

FIG. 3 is a vertical sectional view taken at line 3-3 of FIG. 1;

FIG. 4 is a bottom plan view, partly broken away, of the apparatus shown in FIGS. 1, 2 and 3; and

FIGS. 5 and 6 are exploded perspective views of parts shown in FIGS. 1 to 4 to illustrate details more clearly.

Referring to the drawing, the invention is shown in connection with surface treating apparatus 10 having a pair of rotatable brushes 11 and 12 which project downward beneath a lower part 14 of a hood or base and are arranged to be driven by an electric motor 15 housed in an upright, casing 16 forming an upper part of the base. The upright casing 16 may be fabricated from a suitable rigid plastic and provided with a horizontally disposed wall or rim 16a at its lower end which forms a top for the lower part 14 of the base. The rim 16a extends about the opposing sides and the front of the upright casing 16 and the outer periphery thereof is formed with a downwardly extending flange 161) which merges with the bottom edge of the rear wall of the upright casing 16.

The lower part 14 of the hood or base, which is of oval shape, is provided with an annular member or side wall 17 of elastomeric material like rubber or plastic, for example, to prevent injury not only to the surface treating apparatus itself but also to furniture and wall baseboards which accidentally may be contacted by the apparatus while it is being manipulated over the surface being treated.

The annular member 17 is formed with a horizontal flange 17a at its inner wall surface at a narrow waisted intermediate section and includes top and bottom portions 17b and 170, respectively, which are inclined to the vertical and slope radially outward from the vicinity of the flange 17a. The top portion 17b is formed with an inwardly extending horizontal flange 17d terminating in a vertically disposed collar 17s of annular form. Adjacent to the collar We the flange 17d is recessed at 171 to receive the top edge of an outer rim 18 of a base or frame 19 removably secured by screws 20 in threaded bosses 160! formed at the underside of the rim 16a of the casing 16.

An apertured bottom plate 21 is fixed to the frame member 19 by screws 21b, as shown in FIGS. 3 and 4. The bottom plate 21 is provided with a peripheral edge portion or outer flange 21a which fits snugly against the bottom edge of the outer rim 1% of the frame member 19. When the casing 16 and frame member 19 and bottom plate 21 are connected by the screws 20 and 21b in the manner shown and just described, the top flange 17d of the annular member 17 is tightly held between the bottom edges 16b and 160 of the casing 16 and the top edge of the rim 18 of the frame 19 and the vertical collar 17e bears snugly against the inner surfaces of these parts. Further, the inner flange 17a of the annular member 17 is frictionally held against the underside of the outer flange 21a of the bottom plate 21. With this construction, the annular member 17 serves as the side Wall or skirt of the lower part 14 of the base and overlies and conceals the rim 18 of the frame 19 from view.

The surface treating apparatus is adapted to be manipulated by a handle 22 which includes an elongated rod 22:: whose lower end is connected to the closed end of an inverted U-sh-aped yoke or fork 22b having spaced apart arms 220. The lower ends of the arms 220 are connected to shafts 23 pivotally mounted in brackets 24 which are secured to the frame 19 and disposed in the space 25 between the electric motor 15 and casing 16.

The electrical circuit for the motor 15 includes an electrical cord 15a extending exteriorly of the lower part 14 of the base and adapted to be connected to a source of electrical supply. The cord 15a is provided with a pair of conductors 15b and 15c connected in a circuit (not shown) which includes the motor 15 and a switch 15d. The switch 15d is adapted to be actuated by suitable mechanism 152 cooperating with one of the shafts 23 and arranged so that the switch will remain in an open position when the handle 22 is in an upright position and is moved to a closed position to complete the motor circuit when the handle is moved to an inclined position to manipulate the surface treating apparatus 10. The mechanism =e may include a pedal 15] projecting rearwardly from the lower part 14 of the base and adapted when depressed to release the handle 22 for movement from a locked upright position.

The lower end of the electric motor 15 is mounted on the frame 19 by screws 26, as shown in FIG. 3. A member 27 formed of suitable insulating material is interposed between the frame 19 and the motor '15 to insulate the frame 19 electrically from the motor. To the lower end of the vertical motor shaft 28 is fixed a pinion 29 which meshes with a gear 30 which in turn meshes with a gear 31, as shown in FIGS. 2 and 4. The gears 30 and 31 are alike and journaled in a similar manner to the frame 19. As shown in FIG. 1, the gear 30 is formed with a central opening 32 within which is fixed the lower end of a vertical shaft 33. The shaft 33 extends vertically upward within a cylindrical wall 19a forming a part of the frame 19. A sintered porous sleeve bearing 34 formed of bronze, for example, is disposed Within the cylindrical wall and arranged to seat against an internal shoulder 19b. The upper end of the shaft 33 is formed to receive a spring clip 35 which is adapted to rest against the upper surface of the porous sleeve bearing 34.

The upper enlarged end of the cylindrical wall 19a defines a ring-shaped chamber or Well 36 in which is disposed absorbent material 37 impregnated with a suitable lubricant. The absorbent material 37 bears against the porous sleeve bearing 34 whereby capillary flow of lubricant is effected through the bearing to lubricate the shaft 33. The well 36 is provided with a removable cover 38 which fits over the upper enlarged end of the cylindrical wall 1%.

The brushes 11 and 12 are alike and detachably connected in a similar manner to the gears 30 and 31, respectively. Each of the brushes 11 and 12 include tufts of bristles 40 and a brush back 41. The bottom central portion 42 of each gear 30 and 31 is round and essentially of semispherical form. The hub 41a of each brush back 41 is formed with a central opening 43 having an internal shoulder 44 formed between a narrow intermediate portion and a wider bottom portion and a top portion 45 which is curved and conforms to the round bottom portion 42 of the gears 30 and 31. Thus, the brushes 11 and 12 can assume different angular positions with respect to the vertical axes about which the gears 30 and 31 rotate, whereby the brushes can be in intimate physical contact with surfaces that are not perfectly level.

Each gear 30 and 31 is provided with a hollow sleeve which depends downward from its bottom spherical portion 42 and is slotted axially to provide a plurality of axially extending fingers 46 having enlarged bottom ends 46a. The enlarged ends 46a of the fingers function as radially movable catches which are arranged to engage the internal shoulder 44 in the central opening 43 of the brush back 41.

When either of the brushes 11 and 12 is detachably mounted on the gears 30 and 31 with the brush back opening 43 overlying the catches 46a and the brush is moved axially toward the bottom spherical portion 42 of the gear, the fingers 46 resiliently flex toward one another and, after passing the narrow intermediate portion of the back opening 43, snap radially outward with the catches 46a engaging the internal shoulder 44 to connect the brush to the gear.

When sufficient separating force is applied to the brushes 11 and 12 to remove them from the gears 30 and 31, respectively, the internal shoulders 44, which are inclined to the vertical, act on the catches 46a in such manner that the fingers 46 will flex radially inward to provide clearance between the catches 46a .and the central openings 43 in the brush backs 41, whereby the brushes can be detached from the resilient fingers 46. It will now be understood that the axially extending fingers 46 are realtively stifi in a lengthwise direction and resilient and bendable in directions transverse to their lengths and normally assume first positions in which the catches 46a engage the shoulders 44. As explained above, the fingers 46 are moved radially inward from the first engaging positions responsive to force applied thereto in directions transverse to their length to move the catches 46a to a release position whereby each brush 12 can be detached by grapsing it and manually moving it axially with respect to the fingers 46.

The brush backs 41 are formed with central depressed zones 41b of cylindrical form which encircle the hubs 41a, as best shown in FIG. 5. The depressed Zones 41b are formed with arcuate-shaped slots 410 at diametrically opposite sides of the hubs 41a. At the periphery of the central depressed Zones 41b the backs 41 are provided with a plurality of arcuate-shaped tabs or lugs 41d which extend vertically upward from the backs and are spaced from one another. The gears 30 and 31 are formed with a plurality of arcuate-shaped slots 48 which receive the tabs or lugs 41d when the brushes 11 and 12 are detachably connected to the gears. Hence, the brushes 11 and 12 and gears 30 and 31, respectively, are interlocked, so that positive driving movement will be imparted to the brush backs 41 from the gears 30 and 31. The lugs 41d and slots 48 into which they extend provide a loose connection between the gears 30 and brush backs 41, the loose connection functioning only to render said brush backs 41 turnable with the gears 30.

In order to prevent excessive wobbling of the brush backs 41 at the bottom central portions 42 of the gears 30 and 31, a ring 49 of elastomeric material, such as rubber, for example, is fixed to the underside of each gear. As shown in FIGS. 1 and 5, the rings 49 are formed with buttons 49a removably secured in openings 50 distributed about the gears 30 and 31. The buttons 49a have narrow necks and enlarged heads which are compressed while passing through the openings 50 and, after passing through the openings, expand outward and engage the top surfaces of the gears to connect the rings 49 to the gears.

As best shown in FIG. 1, the resilient rings 49 depend downward from the gears and flare outward to form skirts having outer free ends, the lower extremities of which are above and spaced slightly from ridges 51 of annular form at the top faces of the brush backs 41. With this arrangement, the rings 49 function as supports for the brushes 11 and 12 and prevent excessive wobbling of the brushes. The skirts 49 function to absorb shock when contacted by the brush backs 41 and to minimize the transfer of such shock to the gears 30. At the same time the resilient rings 49 permit some angular movement of the brush backs 41 on the round bottom portions 42 of the gears, whereby the brushes 11 and 12 can assume different angular positions with respect to the vertical axes about which the gears 30 and 31 rotate.

The gears 30 and 31 each include a circular disk 52 which is formed of metal and retained within a body 53 of plastic. The metallic disks 52 preferably are molded within the bodies 53 of plastic in suitable dies to provide unitary gear structures. As shown in FIGS. 1, 5 and 6, the metallic disks include a flat central hub portion 52a having a plurality of spaced openings 52b dis- .tributed about its axis and an outer flat rim portion 520 forming the web portions of the gears 30 and 31 and having a plurality of openings 52d interposed between the openings 50. The disks 52 include intermediate portions 52a of annular form between the hub portions 52a and rim portions 520, the intermediate portions sloping upward and outward from the hub portions 52a to the rim portions 52c. In FIGS. 5 and 6 it will be seen that the arcuate slots 48 are formed at the outer periphery portions of the central hub portions 52a.

The plastic bodies 53 include top and bottom central portions 53a and 5312, respectively. The top central portions 53a are circular and formed with central openings in alignment with the openings 32 in the metal disks 52. The bottom central portions 53b include the central portions 42 which are round and of semi-spherical form and the flexible fingers 46, as shown in FIG. 6. The top and bottom central portions 53a and 53b of the plastic bodies 53 are in intimate physical contact with the top and bottom surfaces of the central hub portions 52a of the metallic disks 52 and are united and joined to one another by portions 53c of the plastic bodies 53 which pass through the openings 52b in the metallic hub portions 52a.

The top and bottom central portions 53a and 53b of the plastic bodies 53 extend radially outward to the inner edges of the arcuate-shaped slots 4-8. The bottom central portions 53b of the plastic bodies 53 are also formed with spaced ears 53b at their peripheries which project radially outward to the intermediate portions 522 of the disks 52 and are in intimate physical contact with the bottom surfaces of the central hub portions 52a of the disks 52 at the regions 52a between the arcuate-shaped slots 48.

The plastic bodies 53 further include outer rim portions 53d having grooves at their inner peripheries to receive the outer peripheries of the metal disks 52. As best seen in FIG. 1, the plastic outer rim portions 53d embrace and snugly fit about the center peripheral edges of the outer rim portions 52c of the disks 52. Gear teeth 53a are formed at the outer peripheries of the plastic outer rim portions 53d.

The top central plastic portions 53a and plastic outer rim portions 530! are joined by ribs 53] which are distributed about the gears 30 and 31 and extend radially outward from the top central portions 53a to the outer rim portions 53d, as shown in FIGS. 1 and 5. Likewise, the bottom central plastic portions 53b and plastic outer rim portions are joined by ribs 53g, as shown in FIGS. 1 and 6. The plastic ribs 53f and 53g are in intimate physical contact with the top and bottom surfaces of the disks 52 and directly opposite one another. As best shown in FIG. 1, each pair of ribs 53 and 53g directly opposite one another are united and joined to one another by portions 53/1 of the plastic bodies 53 which pass through the openings 52d in the outer fiat rim portions 52c of the metal disks 52. Also, the regions 52a of the metal disks 52 may be formed with openings 52k whereby each pair of ribs 53 and 53g directly opposite one another may be united and joined by portions 53k of the plastic bodies 53 which pass through such openings.

When the brushes 11 and 12 are being rotated during operation of the surface treating apparatus 1% the bristles it) are carrying the deadweight load of the apparatus and an upward thrust is transmitted to the gears 30 and 31. Thrust bearing plates 54 are provided between the top central portions 53a of the plastic gear bodies 53 and the underside of the frame 19, as shown in FIGS. 1, 5 and 6. The bearing plates 54 are formed with openings 55 which are distributed about the axes of the shafts 33. Pairs of openings 55 at diametrically opposite sides of the axes of rotation of the shafts 33 are located at different radial distances from the axes. Also, the bottom surfaces of the bearing plates 54 are formed with elongated grooves or slots 56 which are of different lengths and extend radially outward from the openings 55 to the outer periphery of the plates 54, as best shown in FIG. 6.

The underside of the frame 19 is provided with cavities 57 of annular form which are defined by the cylindrical walls 19a and cylindrical walls 19c which are of larger diameter than the walls 1% and encircle the latter. The lower open ends of the cavities 57 are closed by the bearing plates 54 and retain bodies 58 of lubricant therein, such as grease, for example. The bearing plates 54 are provided with a plurality of upright tabs or lugs 59 which are radially disposed and spaced from one another.

The bearing plates 54 are formed with central openings 6t) and loosely mounted on the shafts 33, as shown in FIG. 1. When the brushes 11 and 12 are being driven by the gears 30 and 31 during operation of the surface treating apparatus ltl, the bearing plates 54 are prevented from rotating by the lugs or tabs 59 which extend upward into the bodies 58 of relatively viscous grease. Hence, the bodies 58 of flowable lubricant are sufficiently viscous to act on the tabs 59 and prevent uninhibited rotation of the thrust bearing plates 54 about the axes of the stub shafts 33. The openings 55 in the bearing plates 54 provide a multiplicity of passages for the lubricant to pass from the cavities 57 to the undersides of the bearing plates. At the undersides of the bearing plates 54 the lubricant flows radially outward in the grooves or channels 56 from the openings 55 which are located at the inner ends of the grooves, whereby the lubricant is distributed about the entire undersides of the bearing plates 54- and the top central plastic portions 53a of the gears 3t? and 31.

The bearing plates 54 and plastic bodies 53 of the gears 51) and 31 desirably are formed of a rigid plastic like nylon, for example. Hence, the bearing plates 54 and top central plastic portions 53a both may be formed of a plastic like nylon, for example, which has a relatively small coefficient of friction and inherently possesses such physical properties that it is effectively lubricated by a lubricant like relatively viscous grease, for example. With this arrangement, the upward end thrust of the gears 3i? and 31 during operation of the surface treating apparatus is effectively taken up by the thrust bearing plates 54.

During operation of the surface treating apparatus 10, air is circulated therethrough by a fan 61 fixed to the motor shaft 28, as shown in FIG. 3. The fan 61 is effective to draw air into the space 25 through a plurality of vertical slits 62 formed at the rear side of the casing 16 at the upper part of the base, one of which is shown in HQ. 3. The electric motor includes a housing 15g having a horizontal partition 15h intermediate its ends, whereby air drawn into the space can only flow vertically downward through the interior of the motor 15 to effect cooling thereof. As shown in FIG. 3, air is discharged by the fan 61 from the lower end of the motor housing 15g through a number of passages or openings 63 into a space 64 which is defined by the frame member 19 and the bottom plate 21 and in which the gears and 31 are disposed.

The bottom plate 21 is formed with two openings 2111, one of which is shown in FIG. 1, which are partially closed by the brushes 11 and 12 when they are detachably mounted on the gears 30 and 31, whereby narrow gaps 65 are formed between the openings 21b in the bottom plate and the resilient rings 49 fixed to the gears 39 and 31 and depending downward therefrom. The gaps 65 serve as a first pair of outlets through which air is discharged from the space 64.

The openings 21b, which are formed in horizontally disposed sections of the bottom plates 21 at a level between the gears 30 and 31 and the brushes 11 and 12, respectively, are of smaller size than the gears 39 and 31 and the brush backs 41. The skirts or rings 49 project downward through the openings 21b and cooperate with the upwardly inclined flanges 210 at the openings which are disposed between the plastic rims 53d of the gears 34? and 31 and the skirts 4-9 and at a sufficient height above the bottom edges of the skirts so that they will always be out of the path of angular movement of the brush backs 41, which, of course, is limited by the skirts.

The plastic rims 53d are of greater thickness than the web portions 520 of the gears 30 and 31 and the skirts 49 depend downward from the web portions 52c below the plastic rims 53d. The upwardly inclined flanges 210 at the peripheral edges of the openings 21b extend into the gaps 65 above the bottom edges of the skirts 49 to effect a reversal of the direction of air flow within the gaps before the air is discharged from the outlets defined by the flanges and the skirts.

The slots 410 in the brush backs 41 serve as a second pair of outlets through which air also is discharged from the space 64. When the brushes 11 and 12 are mounted on the gears 30 and 31 and the tabs or lugs 41d on the brush backs 41 extend through the arcuate-shaped slots 48 in the gears, gaps 66 are formed between the slots 48 and tabs 41d through which air in the space 64 can flow toward the central depressed zones 41b of the brush backs 41 and pass through the outlets 41c. As best shown in FIG. 1, the resilient ring-shaped members 49 at the vicinities of the brushes 12 promote flow of air from the gaps 66 through the outlet openings 410. 7

As shown by the arrows in FIG. 1, air is discharged downward through the gaps 65 about the peripheries of the brushes 11 and 12 and air is discharged downward through the slots 410 in the brush backs 41 within the hollow interiors of the brushes.

The gaps 65 on the one hand and the gaps 66 and slots 410 on the other hand are of such size that the fan 61 is capable of maintaining the air in the space 64 at a sufiiciently high pressure to prevent upward flow of air through the gaps 65 and slots 410, so that dust and dirt cannot enter the space 64 which serves as a housing for the gears 30 and 31 and driving pinion 29 at the lower end of the motor shaft 28.

Although a particular embodiment of the invention has been shown and described, it will be apparent to those skilled in the art that various modifications and changes may be made without departing from the spirit and scope of the invention, as pointed out in the following claims.

What is claimed is:

1. The combination with surface treating apparatus having a base (14, 16), at least one member mounted for rotation about a vertical axis at the underside of said base (14, 16), a brush (12) including a back (41) and bristles fixed thereto, means (46, 46a) for mounting said back (41) on said rotatable member (30), said rotatable member (30) and said back (41) having first (42) and second (45) coacting surfaces so constructed and formed that said brush (12) is angularly movable on said rotatable member (30) when mounted thereon by said mounting means (46, 4601), said rotatable member (30) having a hub at its axis of rotation providing said first surface (42), and said brush back (41) and said rotatable member (30) having cooperating interlocking parts (41d, 48) for imparting movement to said brush (12) from said rotatable member (30) when said brush back (41) is connected thereto; of structure to restrain wobbling of said brush (12) comprising a ringshaped member (49) fixed to said rotatable member (30) and forming a skirt depending downward from the underside of said rotatable member (30) and having an outer free end, said skirt comprising elastomeric material embodying resilient physical characteristics and coacting with said brush back (41) to limit angular movement of said brush (12) on said rotatable member (30) and to absorb shock when contacted by said brush back (41) and to minimize the transfer of such shock to said rotatable member (30).

2. Apparatus as set forth in claim 1 in which said skirt (49) has attachment buttons (49a) including compressible head portions and narrower neck portions, said rotatable member (30) being formed with openings (50) of smaller size than said head portions and through which the latter can be inserted when compressed, and said skirt (49) being fixed to said rotatable member (30) by said head portions after being inserted through the openings (50) and released.

3. The combination with surface treating apparatus (10) having a base (14, 16) provided with a downwardly extending side wall (17), at least one member (30) mounted for rotation about a vertical axis at the underside of said base (14, 16), a brush (12) including a back (41) and bristles (40) fixed thereto, means (46, 46a) for mounting said back (41) on said rotatable member (30), said side wall (17) being disposed about said rotatable member (30) and said brush back (41) when said brush (12) is mounted on said rotatable member (30), said rotatable member (30) and said back (41) having first (42) and second (45) coacting surfaces so constructed and formed that said brush (12) is angularly movable on said rotatable member (30) when mounted thereon by said mounting means (46, 46a), said rotatable member (30) having a hub at its axis of rotation providing said first surface (42) and a rim (53d) at its periphery and a web (520) therebetween, and said brush back (41) and said rotatable member (30) having cooperating interlocking parts (41d, 48) for imparting movement to said brush (12) from said rotatable member (30) when said brush back (41) is connected thereto; of structure to restrain Wobbling of said brush (12) and prevent dirt entering the interior of the lower part (14) of said base comprising a member (49) of annular form fixed to said web (520) at a region removed from said rim (53d) and forming a skirt depending downward therefrom, said skirt (49) coasting with said brush back (41) to limit angular movement of said brush (12) on said rotatable member (30), a bottom closure plate (21) fixed to said base (14, 16), said closure plate (21) having a horizontally disposed section (210) at a level between said rotatable member (30) and said brush (12) and formed with an opening (2111) which is of smaller size than said rotatable member (30) and said brush back (41) and through which said skirt (49) projects downward, the edge of the closure plate (21) defining the opening (210) therein being disposed between the rim (53d) of said rotatable member (30) and said skirt (49) and at a sufiicient height above the bottom edge of said skirt (49) so that it will always be out of the path of angular movement of said brush back (41) on said rotatable member (30) which is limited by said skirt (49) 4. The combination with surface treating apparatus (10) having a base (14, 16), an electric motor (15) housed within the upper part (16) of said base with its shaft (28) depending vertically downward therefrom, at least one member (30) mounted for rotation at the underside of said base (14, 16), a brush (12) including a back (41) and bristles (40) fixed thereto; of means (46, 46a) for detachably mounting said brush back (41) on said rotatable member (30) at its axis of rotation, means including said motor shaft (28) for driving said rotatable member (30), said rotatable member having at least one slot (48) at a region removed from its axis of rotation, said brush back (41) having at least one lug (41d) extending upward therefrom into said slot (48) to provide a loose connection therebetween, said loose lug and slot connection functioning only to render said brush back (41) turnable with said rotatable member (30), structure embodied in the apparatus (10) which provides an air passage (25, 15g, 63 and 64) having an inlet (62) and outlet (41c) at the top and bottom parts, respectively, of said base (14, 16), means for circulating air in the passage (25, 15g, 63 and 64) including a rotatable element (61) fixed to said motor shaft (28), said structure providing the passage (25, 15g, 63 and 64) being constructed and formed to circulate air past said motor (15) to effect cooling thereof and subsequently discharge such air at the vicinity of said brush (12), said slot (48) and lug (41d) extending therein defining a gap (66) and forming part of said structure defining the air passage, said brush back (41) having at least one opening (410) therethrough, said last-mentioned opening (410) receiving air flowing downward through said gap (66) and forming the outlet of said passage (25, 15g, 63 and 64) through which air is discharged into said brush (12) at a region radially removed from the periphery thereof, and means (49) at the vicinity of said brush (12) to promote flow of air from said gap (66) to said opening (410) in said brush -back (41).

motor mounted on said frame (19), said motor (15) being housed within said base (14, 16) with its shaft (28) depending vertically downward therefrom to the underside of said frame, at least one member (30) rotatably mounted on said frame (19) at the underside thereof for rotation about a vertical axis, a brush (12) including a back (41) and bristles (41)) fixed thereto, means (46, 46a) for mounting said back (41) on said rotatable member (39), means including said motor shaft (28) for driving said rotatable member (3%)) and said brush (12) mounted thereon, said last-mentioned driving means coacting with said motor shaft (23) being disposed at the underside of and adjacent to said frame (19), said base (14, 16) having a horizontally disposed part (16a) which is adjacent to and overlies said frame (19) and is provided with a downwardly extending flange (16b) at its lower edge; of structure providing a vertically extending side wall (17 for said base (14, 16) which is formed of elastomeric material and extends vertically through a zone at the underside of said frame (19) which is coextensive with said rotatable member (311) and said brush back (41) when said brush (12) is mounted on said rotatable member (34) and disposed about the latter, the upper part of said side wall (17) having an inwardly extending flange (17d), said frame (19) having a vertically extending rim (18) at its outer periphery, the rim (18) being joined to said frame at a region between its top and bottom edges, said inwardly extending flange (17d) of said side wall (17) being disposed between the downwardly extending flange (16b) of said base part (16a) and the top edge of said rim (18), said side wall (17) being disposed about and extending below said rim (18) and including a part (17a) acting against the bottom edge of said rim (18), and fastening means coacting with the horizontally disposed part (16a) of said base (14, 16) and the portion of said frame (19) which it overlies for detachably connecting said frame (19) to said base part (16a) to grip and tightly hold the inwardly extending flange (17d) of said side Wall (17) between the downwardly extending flange (16b) of said base part (16a) and the top edge of said rim (1S).

6. The combination with surface treating apparatus (10) having structure including rotatable means adapted to be positioned over a surface for rotation about a vertical axis and moved over the surface, a brush (12) including a back (41) and bristles projecting from the bottom side thereof, said back (41) having a centrally disposed opening (43) extending therethrough defining a shoulder (44) at a region axially removed from the top side thereof; of means for detachably connecting said brush (12) to said rotatable means (30) with the top side of said brush back (41) facing first and second zones at the underside of said rotatable means (30), said connecting means comprising fastening structure (46) which is fixed to the first zone of said rotatable means (3%) at the immediate vicinity of its axis of rotation and extends axially downward from the underside thereof through the opening (43) in said brush back (41) from the top side thereof toward said shoulder (44), said axially extending fastening structure (46) having a plurality of axially extending fingers (46) having radially movable Catches (46a), said fingers (46) being relatively stiff in a lengthwise direction and resilient and bendable in directions transverse to their length and normally assuming first positions in which said catches (46a) are positioned to engage said shoulder (44) at the opening (43) said catches (46a) being movable radially inward therefrom to a release position responsive to force applied thereto in directions transverse to their length whereby said brush (12) can be detached from said fastening structure (46) by grasping said brush and moving the latter axially with respect to said fingers (46), the second zone (42) of said rotatable means being of semispherical form and disposed about the first zone, the top side of said back (41) at the opening (44) having a surface conforming with that of the second zone so that said back (41) is angularly movable on said rotatable means (30) when said brush (12) is held thereon by said fastening structure (46), said fastening structure (46) and the second zone (42) of semispherical form being integrally joined to one another and forming a unitary part (5312) of said rotatable means (30), and said brush back (41) and said rotatable means (30) having cooperating interlocking parts (41d, 48) for imparting movement to said brush (12) from said rotatable means (30) when said brush back (41) is connected thereto.

7. Apparatus as set forth in claim 6 in which said rotatable means (30) includes a circular disk (52) of metal and a single body (53b) of plastic fixed to the bottom of said disk (52) and defining said fastening structure (46) and said second zone (42) of semi-spherical form.

8. The combination with surface treating apparatus (141) having structure including rotatable means (30) adapted to be positioned over a surface for rotation about a vertical axis and moved over the surface, a brush (12) including a back (41) and bristles (40) projecting from the bottom side thereof, said back (41) having a centrally disposed opening (43) extending therethrough defining a shoulder (44) at a region axially removed from the top side thereof; of means for detachably connecting said brush (12) to said rotatable means (30) with the top side of said brush back (41) facing first and second zones at the underside of said rotatable means (30), said connecting means comprising fastening structure (46) which is fixed to the first zone of said rotatable means (30) at the immediate vicinity of its axis of rota tion and extends axially downward from the underside thereof through the opening (43) in said brush back (41) from the top side thereof toward said shoulder (44), said axially extending fastening structure (46) having a plurality of radially movable catches (46a) which are positioned to engage said shoulder (44) at the open ing (43) and movable radially inward therefrom to a release position, the second zone (42) of said rotatable means being of semi-spherical form and disposed about the first zone, the top side of said back (41) at the opening (43) having a surface (45) conforming with that of the second zone so that said back (41) is angularly movable on said rotatable means (30) when said brush (12) is held thereon by said fastening structure (46), said fastening structure (46) and the second zone (42) of semi-spherical form being integrally joined to one another and forming a unitary part (53b) of said rotatable means (30), and said brush back (41) and said rotatable means (31)) having cooperating interlocking parts (41d, 48) for imparting movement to said brush (12) from said rotatable means (31)) when said brush back (41) is connected thereto, an electric motor (15) and gear means (29) for driving said rotatable means (30), said rotatable means (30) including a circular disk (52) of metal, a toothed tire which is operatively associated with said gear means (29) and comprises a first plastic member (53d) of annular form having a groove at its inner periphery which receives the outer peripheral edge of said disk (52), a second plastic member (5311), means (530) for fixing said second plastic member (53b) to the bottom of said disk (52) at the vicinity of the axis of rotation of said rotatable means (3%), and means (53g) connecting said first (53d) and second plastic members (53b), said last-mentioned connecting means (53g) being formed of plastic and integral with said first (53d) and second (531)) plastic members and extending radially outward from said second plastic member (53b) in intimate physical contact with the bottom of said disk (52), and said second plastic member (5312) comprising said unitary part formed by said integrally joined fastening structure (46) and the second zone (42) of semi-spherical form.

9. Apparatus as set forth in claim 8 in which said disk is formed with apertures and which includes a third plastic member (53a) at the top of said metal disk (52), said means for fixing said second plastic member (53b) to the bottom of said disk (52) comprising plastic elements (530) which extend through .said apertures and are integral with said second (53b) and third (53a) plastic members and function as rivets to hold said plastic members (53a, 53b) together at the vicinity of the axis of rotation of said rotatable means (30), and means (53)) connecting said first (53d) and third (53a) plastic members, said last-mentioned connecting means (53 being formed of plastic and integral with said first (53d) and third (53a) plastic members and extending radially outward from said third plastic member (53a) in intimate physical contact with the top of said disk (52).

10. In surface treating apparatus a frame (19), an electric motor mounted on said frame (19), a shaft (28) driven by said motor (15) which depends downward therefrom to the underside of said frame (19), at least one gear rotatable about a vertical axis at the underside of said frame (19), means including a pinion (29) at the lower end of said motor-driven shaft (28) for driving said gear (30), said frame (19) having a bearing seat (19a, 1%), a gear shaft (33) fixed at its lower end to the hub portion (32) of said gear (30) and extending upward into said frame (19), a bearing (34) seated in said bearing seat (19a, 19b) for journaling said gear shaft (33), a brush (12) including a back (41) and bristles fixed thereto, means (46, 46a, 41d and 48) for detachably connecting said brush back (41) to the underside of said gear (30) in interlocking relation therewith, and a thrust bearing to relieve the upward thrust transmitted from said brush (12) to said gear (30) comprising a first backing-up thrust plate (54) at the underside of said frame (19) through which said gear shaft (33) extends and with respect to which said gear shaft (33) is rotatable and a second thrust plate (53a) which is disposed about the axis of said gear shaft (33) and fixed to the top side of said gear (30) and against which said first thrust plate (54) is adapted to bear, and the underside of said first thrust plate (54) having a pluralitybf grooves (56) adapted to receive lubricant.

11. Apparatus as set forth in claim 10 in which said first thrust plate (54) is provided with a plurality of openings (55), each of said last-mentioned openings (55) communicating with at least one of said grooves (56) at the underside of said first thrust plate (54), and means (57) to supply lubricant from a source of supply to the top side of said first thrust plate (54).

12. Apparatus as set forth in claim 11 in which said grooves (56) are distributed about the underside of said first thrust plate (54) and extend inward from zones adjacent to the periphery thereof, the openings communicating with said grooves (56) at regions thereof removed from said zones.

13. Apparatus as set forth in claim 10 in which said first thrust plate (54) is provided with a plurality of openings (55), each of said last-mentioned openings (55) communicating with at least one of said grooves (56) at the underside of said first thrust plate (54), said frame (19) including structure defining a cavity (57) open at the bottom, and said first thrust plate (54) being arranged to close the opening in the cavity (57), said cavity (57) being adapted to hold a body of lubricant which is flowable therefrom through the apertures (55) in said first thrust plate (54).

14-. Apparatus as set forth in claim 13 in which said first thrust plate (54) is provided with elements (59) which extend upward into said cavity (57), the body of fiowable lubricant adapted to be held in said cavity (57) being sufficiently viscous to act on said elements (59) and prevent uninhibited rotation of said first thrust plate (54) about the axis of said gear shaft (33).

References (Cited by the Examiner UNITED STATES PATENTS 1,519,616 12/24 Herr 1549 1,650,690 11/27 Cavicchi. 1,920,624 8/33 Bilde 15-49 1,948,815 2/34 Gruendel l550 1,958,658 5/34 Engberg et al 15-49 X 2,785,424 3/57 McMaster et a1. 1549 2,867,825 1/ 59 Ripple 1549 2,960,705 11/60 Nilsson et a1. 1549 X 3,022,529 2/62 Bonfanti 1549 FQREIGN PATENTS 71,280 7/50 Denmark. 517,926 3/55 Italy. 598,519 10/59 Italy.

CHARLES A. WILLMUTH, Primary Examiner. 

1. THE COMBINATION WITH SURFACE TREATING APPARATUS (10) HAVING A BASE (14, 16), AT LEAST ONE MEMBER (30) MOUNTED FOR ROTATION ABOUT A VERTICAL AXIS AT THE UNDERSIDE OF SAID BASE (14, 16), A BRUSH (12) INCLUDING A BACK (41) AND BRISTLES (40) FIXED THERETO, MEANS (46, 46A) FOR MOUNTING SAID BACK (41) ON SAID ROTATABLE MEMBER (30), SAID ROTATABLE MEMBER (30) AND SAID BACK (41) HAVING FIRST (42) AND SECOND (45) COACTING SURFACES SO CONSTRUCTED AND FORMED THAT SAID BRUSH (12) IS ANGULARLY MOVABLE ON SAID ROTATABLE MEMBER (30) WHEN MOUNTED THEREON BY SAID MOUNTING MEANS (46, 46A), SAID ROTATABLE MEMBER (30) HAVING A HUB AT ITS AXIS OF ROTATION PROVIDING SAID FIRST SURFACE (42), AND SAID BRUSH BACK (41) AND SAID ROTATABLE MEMBER (30) HAVING COOPERATING INTERLOCKING PARTS (41D, 48) FOR IMPARTING MOVEMENT TO SAID BRUSH (12) FROM SAID ROTATABLE MEMBER (30) WHEN SAID BRUSH BACK (41) IS CONNECTED THERETO; OF STRUCTURE TO RESTRAIN WOBBLING OF SAID BRUSH (12) COMPRISING A RINGSHAPED MEMBER (49) FIXED TO SAID ROTATABLE MEMBER (30) AND FORMING A SKIRT DEPENDING DOWNWARD FROM THE UNDERSIDE OF SAID ROTATABLE MEMBER (30) AND HAVING AN OUTER FREE-END, SAID SKIRT COMPRISING ELASTOMERIC MATERIAL EMBODYING RESILIENT PHYSICAL CHARACTERISTICS AND COACTING WITH SAID BRUSH BACK (41) TO LIMIT ANGULAR MOVEMENT OF SAID BRUSH (12) ON SAID ROTATABLE MEMBER (30) AND TO ABSORB SHOCK WHEN CONTACTED BY SAID BRUSH BACK (41) AND TO MINIMIZE THE TRANSFER OF SUCH SHOCK TO SAID ROTATABLE MEMBER (30). 